Vol. XIII] EVANS— HEPATIC At. OF CALIFORNIA 



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and usually by the presence of delicate striolations on the 

 cuticle. In some cases, especially toward the margins of the 

 leaves, very minute trigones with concave sides can be dem- 

 onstrated, but they are so indistinct that they are practically 

 negligible. In /. pendletonii the leaves are approximately 

 orbicular and do not show the tapering found in /. cordifolia, 

 although the rounded basal portions are not dissimilar in the 

 two species. The leaf-cells yield further distinctions. In 

 /. pendletonii the median cells are mostly 40-50[i. long and 

 25-30{a wide, while the marginal cells are 27-32[a in di- 

 ameter; in /. cordifolia the median cells are mostly 40-45 X 

 20-30[x, while the marginal cells are only 20-23(a in diam- 

 eter, the cells thus showing a more marked decrease in size 

 in passing from the median portion outward. In /. pendle- 

 tonii, moreover, it is usually possible to demonstrate distinct 

 trigones, especially in the marginal portions of the leaves, but 

 the striolations are very indistinct although not entirely 

 absent. 



Pearson emphasizes as a characteristic feature of his species 

 the presence of two layers of cells in the basal portion of the 

 leaf, the two layers not being "regularly arranged cell on 

 cell" but crossing each other. This two-layered portion does 

 not stretch entirely across the leaf but occupies a vaguely 

 defined area toward the ventral side. In poorly developed 

 leaves the area is much reduced in size and may be absent 

 altogether. Just how distinctive this feature really is remains 

 to be determined, since very few species of Jungermannia 

 have been studied from this particular point of view. It is 

 not, however, absolutely distinctive. The robust Norwegian 

 material of /. cordifolia, for example, collected by E. Jorgensen 

 at Gulen in Sordfjord and distributed in Schiffner's Hepaticse 

 europaeae (No. 394), shows small basal leaf areas where the 

 cells are in two layers ; and the same thing is true of some of 

 the more vigorous North American specimens examined by 

 the writer. None of these, however, are comparable in dis- 

 tinctness with the much larger areas found in /. pendletonii. 



The male inflorescence of /. pendletonii was unknown to 

 Pearson, but he described the perichaetial bracts and perianths 

 and illustrated them in a supplementary note. 25 According 



"Bryologist 23: 84, 85. f. 1-3. 1920. 



